1. Field of the Invention
The present invention relates to a combustion gas turbine control valve and more particularly, to a combustion gas turbine control valve for regulating the inlet temperature of an indirect fired gas turbine at the turbine expander inlet, useful in an indirect fired gas turbine power generation system.
2. Description of the Related Art
In a conventional open cycle gas turbine, a cycle compressor raises the pressure of air from the atmosphere to a higher pressure and delivers this higher pressure to a combustion chamber to be mixed with a fossil fuel which is burned. The resulting high pressure, high temperature products of combustions are expanded through a turbine expander to drive a load such as an electric generator and the previously mentioned cycle compressor, used to compress the atmospheric air for the cycle.
A prior art power generation combined cycle system is shown in FIG. 1 at 10. In this system an ambient air stream of atmospheric air 12 is directed to a compressor portion 14 of a gas turbine, having a rotating shaft linking portion 14 with turbine expander 18, wherein the temperature and pressure of the air are increased by the compressor portion 14, from atmospheric to from about 60 to 600 psia and a temperature of from about 200.degree. F. to about 1200.degree. F. The high pressure stream of air then leaves the compressor portion 14 through passage 15 and passes to one or more combustors at 101 wherein a fossil fuel is added and burned thus increasing the temperature of the constituents in the gas stream or generally referred to as the products of combustion. The hot products of combustion at 17 are delivered to the inlet of the turbine expander 18. The turbine expander 18 drives the cycle compressor 14 and an electric alternator temperature of the constituents in the gas stream or generally referred to as the products of combustion. The hot products of combustion at 17 are delivered to the inlet of the turbine expander 18. The turbine expander 18 drives the cycle compressor 14 and an electric alternator 20 which produces electric power 222. The turbine exhaust gases 24 can be directed to a steam generator 36 and the steam thus generated is used to drive a steam cycle which includes a steam turbine 25. The steam turbine in turn drives an alternator that produces additional electric power. When a steam cycle is added, the power cycle is referred to as a "combined cycle".
In the embodiment shown, the turbine exhaust gas 24 passes through a steam generator 36 producing steam that is expanded through a steam turbine 25 to produce additional electric power before being discharged to the atmosphere.
In prior art cycles, the quantity of electric power generated by the cycle is controlled by modulating the fuel flow to the combustor 101, thus changing the temperature of the inlet gas stream into the turbine expander 18 from full fuel energy input to the machine to zero energy input in 100 milliseconds or less. Thus, permitting full control of the rotational speed of the gas turbine.